Relationship between respiratory control and feeding in the developing infant.

Simultaneous breathing and nursing from a bottle or breast requires intricate coordination of the muscles that serve both respiration and feeding. During the buccopharyngeal phase of feeding reflex input to the brainstem from the oropharynx and larynx, as well as suprabulbar and chemoreceptor areas controls the sequential activity of the muscles of deglutition. Coordinated development of buccopharyngeal functions generally occurs by 35 weeks post-conceptional age in infants, but can be disrupted by respiratory disease or neuropathology. During the oesophageal phase of feeding, the bolus of food traverses the oesophagus and lower oesophageal sphincter, whose tone is also regulated by nuclei in the brainstem and modulated by respiratory drive. Control of the lower oesophageal sphincter gradually develops postnatally in premature infants. Although symptomatic gastro-oesophageal reflux can be problematic for the term or preterm infant, it does not appear that reflux is a common stimulus for apnoea of prematurity.